JPH04312901A - Production of superconducting coil using superconductive ceramic wire - Google Patents

Abstract

PURPOSE:To produce a product which has excellent ductility, malleability and bendability by filling the inside of a hollow supporting body with powder superconductive ceramic material, baking the supporting body so as to produce superconductive wire and coiling the wire. CONSTITUTION:The inside of a hollow supporting body 2 composed of metal or metal compound is filled with superconductive ceramic material 3. As the superconductive ceramic material, copper oxide ceramics (A1-X, BX)YCuZOW is used, where, A=Y, Gd, etc., B=Ba, Sr, etc., X=0-1, Y=2.0-4.0, Z=1.0-4.0, W=4.0-10.0). Then, the supporting body 2 is baked to oxidize the ceramics and superconductive material is formed. Such process is repeated several times and superconductive ceramics 3 which has a hollow 4 in the hollow supporting body 2 is formed. Then, the whole body is drawn into wire and superconductive wire 1 is produced. Then the superconductive wire 1 is coiled.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a coil using a ceramic superconducting material.

[0002] The present invention uses superconducting ceramic wire drawing to
For example, the present invention relates to a method for manufacturing a superconducting magnet or a coil used in a power storage device.

0003

2. Description of the Related Art Hitherto, metal materials such as Nb-Ge (for example, Nb3Ge) have been used as superconducting materials. Since this material is a metal, it has high ductility, malleability, or bendability, and therefore, useful applications include coils for superconducting magnets and coils for power storage.

However, this metallic superconducting material is Tc (
The superconducting critical temperature (hereinafter referred to as Tc) was small, at only 23K or lower. However, if we consider its industrial application, this Tc should be 100K or more, and Tco (temperature at which electrical resistance becomes zero)
It is extremely important that the value be 77K or greater.

[0005] Recently, copper oxide ceramic materials have attracted attention as such superconducting materials.

[0006]

[Problems to be Solved by the Invention] This copper oxide ceramic does not necessarily have sufficient ductility, malleability, and bendability. In addition, it has another drawback in that it is extremely difficult to process after molding. Therefore, there was no known method of producing a superconducting coil by drawing wire using copper oxide ceramics.

[0007]

SUMMARY OF THE INVENTION The present invention uses a metal or metal compound hollow support (also referred to as a pipe or sheath) as a material. The inside of such a hollow support is filled with a solution obtained by mixing, melting, or gelling materials to become a superconducting ceramic material, or a superconducting ceramic material without using a solvent. This filling is performed by temporarily blocking one side of the hollow pipe and injecting from the other side. Thereafter, by heating and firing, this outer ceramic is oxidized and transformed into a superconducting material. The ceramic material having superconductivity in the present invention is, for example, copper oxide ceramic (A1-x Bx)yCuzOw x=0
~1, y=2.0 ~4.0 preferably 2.5 ~
3.5, z=1.0 ~ 4.0 preferably 2.5 ~
3.5, w=4.0 ~ 10.0 preferably 6.0 ~
It is 8.0. A is a group 3a in the periodic table of elements, such as Y (yttrium) or Gd (gadolinium).
These are lanthanide elements such as Yb (Ytterbium) and Yb (Ytterbium). In addition, B is an element group 2a of the periodic table, for example, Ba
(Value) or Sr (Strontue)
Calcium), Ca (Calcium). The periodic table of elements in this specification is based on the Physical and Chemistry Dictionary (Iwanami Shoten 1).
(Published April 1, 1963).

[0008] In the ceramics used in the present invention, elements other than those mentioned above can be added to A and B.

In the present invention, when the inside of the hollow support is filled with a solution obtained by mixing, melting, or gelling materials to become a superconducting ceramic material, a first layer is formed on the inner wall.
A superconducting ceramic material is coated as a layer of superconducting ceramic material, and after the first layer of ceramic material is sufficiently solidified, the same process is repeated to coat a second layer of ceramic material. That is valid. In that case, the type of A or B and the values of X, Y, Z, and W may be partially changed. In the present invention, such ceramics are heated and wire-drawn (stretched into a linear shape), so that the outer diameter is reduced and the wire is stretched from one side to the other to form a thin and long structure.

In the method of the present invention, the ceramic formed inside the pipe of metal or its compound is sufficiently oxidized,
In order to transform and optimally crystallize a material represented by the general formula (A1-x Bx)yCuzOw that exhibits superconductivity, it is important that sufficient oxygen be added to this ceramic. The method of the present invention can sufficiently control the atmosphere even for ceramic pipes with a large amount of metal on the outside.

The coil obtained by the method of the present invention is obtained by winding the drawn superconducting wire obtained by the above manufacturing method into a coil shape. In some cases, a heating step may be added after winding.

0012

[Operation] The present invention has made it possible to produce a superconducting coil using superconducting ceramic wire drawing, which was previously thought to be impossible. This coil can be used, for example, to make a superconducting magnet. Furthermore, by connecting the starting point and ending point of this coil to each other with ceramics having zero electrical resistance, an endless coil can be obtained. This coil can be used as a coil without current loss, that is, as a device for storing electrical energy.

Embodiments of the present invention will be described below with reference to the drawings.

[0014]

【Example】

"Example 1" In this example, (A1-x Bx)yCu
In zOw, Y as A, Y2O3, B as B
BaCO3 was used as a, and CuO was used as Cu. Each of 99.95% or more manufactured by Kojundo Kagaku Co., Ltd. was used. Use these to adjust x, y, z, w (YBax
) Cu3O6 ~8. Mix these raw materials in an agate mortar and mix it once at 300 kg/cm.
The mixture was pressurized at a pressure of 2.2°C to form a tablet and pre-calcined in the air at 700°C for 3 hours, and then at 1000°C for 10 hours. Furthermore, these were crushed again. And the average particle size is 10
The thickness was set to 0 μm or less, for example, about 10 μm. This mixture was sealed in a capsule and heated again to 500K.
It was pressed at a pressure of g/cm2 to form a tablet. This was then subjected to main firing at 800 to 1000°C for 10 hours in an oxidizing atmosphere, such as the air.

Next, the Tc onset of this main firing was 95
It is confirmed from the voltage-current-temperature characteristics that Tco is 77K or higher.

This tablet was again made into a fine powder. The average particle diameter was adjusted to be 100 μm or less to 0.05 μm, for example, 3 μm. In this process, efforts were made to basically prevent the crystal structure from being destroyed during this pulverization.

This powder is mixed or dissolved in a liquid such as a fluorocarbon solution or an alcohol such as ethanol or other liquid.

This solution is transferred to a hollow support, the metal pipe (2) shown in FIG. 1, such as copper or a copper compound (
For example, a NiCu compound) was poured into the interior of the compound, blocking the other side. This pipe is rotated and vibrated up and down to ensure that the ceramic particles adhere to the inner wall with a uniform thickness.
It was heated to a temperature of 0.00°C.

In this manner, the solvent inside the hollow pipe could be removed, and the inner wall of the hollow pipe was coated with ceramic particles (3).

At this time, in order to make it easier to adhere to the inner wall, it may be mixed with propylene glycol, octyl alcohol, peptyl alcohol, etc. to form a paste.

[0021] After that, oxygen or a mixed gas of oxygen and argon is introduced into the hollow part of the ceramic adhered to the inner wall and dried, and the ceramic is oxidized to a temperature of 500 to 110%.
Firing was performed at 0°C, for example, 600°C for 3 hours, and then at 800°C for 15 hours.

By repeating this process 1 to 5 times, it became possible to deposit this ceramic material inside the pipe to an average thickness of 50 μm to 1 cm (typically 0.5 to 5 mm). Thus, superconducting ceramics (3) are placed inside the hollow support (2) as shown in Figure 1.
It was possible to make a pipe (1) having a hollow part (4) using the superconducting ceramic of the present invention.

In this example, the pipe used was an annular hollow support. However, the shape may be a square hollow support. Other shapes are also possible.

[0024] In such a superconducting ceramic pipe,
Tc is 5 to 20 higher than Tc when made with a tablet etc.
A low value of K was obtained. However, this improves Tc in early tablets and can be further improved. Further, this length can be varied from several cm to several tens of meters depending on the design. Further, the thickness can be varied from several mm to several cm in diameter.

``Example 2'' In this example, a hollow organic material hype smaller than the inner diameter of the hollow hype is placed in advance, and during that time, the fired superconducting material made in the intermediate step of Embodiment 1 is heated. Fill with crushed material.

[0026] This powder is then filled. When all of this was heated while oxygen was flowing through the inner diameter of the organic material pipe, the organic material carbonized at about 300 degrees Celsius, and as the temperature rose further, it vaporized as carbon dioxide gas and was completely removed. . Afterwards, the filled ceramics were oxidized to become a superconducting material. In this case 600 to 11
This was accomplished by heating at 00°C, for example 800-1000°C, for 10-20 hours.

[0027] In this way, it was possible to produce a metal pipe having a hollow space and having superconducting ceramics provided therein. In this embodiment, it is effective to fill the superconducting ceramic material between the hollow supporting body and the hollow auxiliary body by pouring a powder or a paste of easily vaporized organic material into the superconducting ceramic material in the form of a paste. Other items not described are the same as in Example 1.

Example 3 This example started with the hollow pipe formed in Example 1 or 2. This is 8
00 to 1100°C, for example, 1000°C. Annealed copper was used for the outside of the pipe. It has a low melting point of 1083℃,
This is because it is highly malleable and ductile. This is to prevent the generation of cracks by applying residual stress at the same time as the heat treatment of the superconducting ceramic material.

[0029]Actually, the diameter of the copper pipe is 10mm (outer diameter)
, 8 mm φ (inner diameter), the average thickness of the ceramic is 3 mm, and the hollow part is approximately 2 mm φ. The whole was heated from the outside, and in order to stretch the whole and make it into a long wire, a squeeze rod jig was passed through it while heating it. The diameter of this pipe was then reduced, and the hollow part was completely eliminated.

[0030] Thus, the outer diameter of such a pipe is about 6 mm.
, the length could be extended to about three times that of the starting material. With the development of technology, it is possible to reduce this diameter to 1 to 2 mm and further increase the length after drawing by 50 to 5000 times.

"Example 4" This example is (A1-X B
x) In yCuzOw, A is Yb, B is B
A was used. Further, in this example, the raw material powder was used as it was, and was densely packed inside the metal pipe. As a result, even after forming into a pipe shape, Tco could be maintained at 85K. The rest is the same as in Example 1 and Example 2.

[0032]

[Effects of the Invention] According to the present invention, it has become possible to produce a superconducting coil using superconducting wire drawing, which was previously considered impossible. This coil can be used, for example, in a superconducting magnet. Moreover, the coil of the present invention is covered with a metal or a metal compound on the outside, and has a superconducting ceramic material on the inside. With this configuration, welding to the outside is also possible.
For example, it can be used as part of an electrical device.

[0033] The present invention can be applied in addition to the above examples, and is considered to greatly contribute to the development of industry.

[Brief explanation of the drawing]

[Figure 1] Superconducting ceramic wire drawing used to produce the coil of the present invention

Claims (3)

[Claims] 1. A superconducting ceramic comprising the steps of: filling a superconducting ceramic material inside a metal or metal compound support; and winding the filled superconducting ceramic material together with the support into a coil shape. Method for manufacturing superconducting coils using wire drawing 2. A step of filling a superconducting ceramic material inside a metal or metal compound support, a step of heating from the outside, a step of drawing the entire superconducting ceramic wire, and forming the drawn superconducting ceramic wire into a coil shape. A method for producing a superconducting coil using superconducting ceramic wire drawing, comprising a winding step. 3. A step of filling a superconducting ceramic material inside a metal or metal compound support;
Preparation of a superconducting coil using superconducting ceramic wire drawing, characterized by comprising a step of heating the drawn superconducting ceramic wire to 1100° C., a step of stretching the entire wire and drawing the superconducting ceramic wire, and a step of winding the drawn superconducting ceramic wire into a coil shape. Method